body{
    margin: 0;
    font-family: "宋体"
}
.w960{
    width: 960px;
    margin: 0 auto;
}


header{
    width: 100%;
    height: 60px;
    background-color: white;
    border-bottom: 2px solid #999;
    padding: 10px 0;
    box-sizing: border-box;
    position: fixed;
    top: 0;
    z-index: 1;


}

header img{
   
    height: 40px;
    float: left;
}

li{
    list-style: none;}
    a{
        text-decoration:none;
        color: black;

    }
    a:hover{
        color: orange;
    }
    ul{
        float: right;
        margin: 8px 0;
    }
li{
    display: inline-block;
margin-left: 20px;
}
body>img{
    width: 100%;
    margin-top: 60px;
}
section img{
    width: 960px;
}
main p{
    text-indent: 40px;
    color: gray;
    line-height: 32px;
    margin-bottom: 50px;
    font-size: 20px;
}
main h1{
    color: orange;
    font-size: 30px;
    
}
main h1:before{
    content: "✽"
}
section .tongxue{
    width: 960px;
    height: 550px;
    background-image: url(images/classmates.jpg);
    position: relative;
}
section .tongxue img:nth-child(1){
    width: 220px;
    height: 220px;
    border: 3px solid white;
    border-radius: 50%;
    position: absolute;
    left: 20px;
}
section .tongxue img:nth-child(2){
    width: 340px;
    height: 340px;
    border: 3px solid white;
    border-radius: 50%;
    position: absolute;
    bottom: 50px;
    left: 200px;
}
section .tongxue img:nth-child(3){
    width: 280px;
    height: 280px;
    border: 3px solid white;
    border-radius: 50%;
    position: absolute;
    right: 60px;
    top: 30px;

}
address{
    color: gray;
    font-size: 20px;
    font-style: normal;
    margin: 50px 0 100px;
}
hr{
    color: gray;
}







    
